Control device for a grinding machine

ABSTRACT

A grinding machine having a grinding disc with a hood. A dressing device is associated with the disc and the hood has a moveable part with a coolant nozzle thereon which supplies coolant to the working region of the disc. Drives are provided to move the dressing device toward and away from the wheel and to adjust the position of the part of the hood and the coolant nozzle and are so interconnected that the coolant nozzle is adjusted in position each time the dressing device dresses the disc whereby the coolant is always directed to the proper region.

United States Patent Koppenwallner 5] July 31, 197 3 [54] CONTROL DEVICEFOR A GRINDING 3,641,714 2/1972 Hiroaki 51/165137 MACHINE [75] Inventor'53: ggf zg der Primary Examiner0thell M. Simpson Att0rneyWalter Becker[73] Assignee: Fortuna-Werke Maschinenfabrik 7 AG, Stuttgart-BadCannstatt,

: Germany [22] Filed: Sept. 1, 1971 ABSTRACT [211 App]. N9" 176,993 Agrinding machine having a grinding disc with a hood. A dressing deviceis associated with the disc and the Foreign Aliplicafion Priority Datahood has a moveable part with a coolant nozzle thereon Sept. 5, 1970Germany P 20 44 147.8 which supp es coo ant to the wo g eg o of thedisc. Drives are provided to move the dressing device [52] US. Cl5l/l65.87, 51/356, 125/11 R toward and away from the wheel and to adjustthe posi- [51] Int. Cl B24b 49/00, B24b 55/02 tion of the p r f the hoodn h coolant nozzle and [58] Field of Search 51/165.87, 165.89, are ointerconnected that the coolant nozzle is ad- 51/356; 125/1 1 R, 1 1 NTjusted in position each time the dressing device dresses the discwhereby the coolant is always directed to the [5 References Cited properregion.

UNITED STATES PATENTS 11/1964 Fant et a1 51/165.87

15 Claims, 3 Drawing Figures PAIENIEU JUL3 1 191a SHEEY 1 OF 3 PATENIEDJUL 3 1 I973 SHEET 3 BF 3 CONTROL DEVICE FOR A GRINDING MACHINE Thepresent invention relates to a control device for a grinding machineand, more specifically, for the feeding device of a dressing apparatus.Devicesof this type, for instance, with dressing diamonds, diamondrolls, or steel rolls, are generally employed in grinding machines forrestoring the sharpness and true shape of the grind ing disc. Thefeeding of the dressing tool is with the individual post-machining'operations respectively effected by relatively small amounts, buttaking into consideration the life span of a grinding disc,correspondingly long total feeding strokes result in view of thegenerally high volume of wear.

Aside from the dressingapparatus, the grinding machines are equippedwith various machine elements which have to be adjusted in conformitywith the diameter of the grinding disc. In this connection there may bementioned so-called cover elements, such as caps,

slides, or the like, which are arranged within the region of thegrinding disc and which are joumalled on the protective hood for thegrinding disc and are supposed alwaysto maintain as slight a distanceaspossible from the circumference of the grinding disc. In thisconnection there may also be mentioned the customary feeding means forthe coolant which likewise must have a predetermined distance from thecircumference of the grinding disc. The post-setting of the abovementioned machine elements requires considerable service and sometimeseven requires a stoppage of the operation while in addition thereto theoperator has to pay considerable attention to these machine elements.Therefore, it would be desirable to have the adjustment of machineelements of the above mentioned type effected automatically inconformity with the respective diameter of the grinding disc.

Consequently, it is an object of the present invention to provide acontrol'device which, while relatively simple in construction, willautomatically adjust machine elements in conformity with the diameter ofthe grinding disc.

This object and other objects and advantages of the invention willappear more clearly from the following specifications in connection withthe accompanying drawings, in which:

FIG. 1 diagrammatically illustrates a vertical section perpendicular tothe grinding spindle axis through a circular grinding machine with adressing device and with adjustable protective hood cap according to theinvention.

FIG. 2 diagrammatically illustrates a section through the machine ofFIG. I along a vertical plane.

FIG. 3 is a control and operating diagram of the control deviceaccording to the invention for adjusting a dressing device and aprotective hood cap according to FIG. 1 and 2.

The control device according to the invention for the feeding device ofa dressing apparatus is characterized primarily in that the feedingdevice is with regard to its movement relative to the grinding devicecoupled to the adjusting device of a machine element, especially a hoodand/or a coolant supply means, in conformity with the diameter of thegrinding disc.

In other words, the invention takes advantage of the high precision ofthe already present control device for feeding the dressing means foradjusting other machine parts or elements in conformity with thediameter of the grinding disc. The required additional structuralelements are relatively few because, aside from the adjusting devicenecessary at any rate in connection with automation with pertainingdrive of the adjustable machine element, only a coupling orsynchronization of the dressing-feeding device on one hand and theadjusting device of the adjustable machine element on the other hand areadditionally required.

Referring now to the drawings in detail and FIGS. 1 and 2 thereof inparticular, the cylindrical grinding machine illustrated thereincomprises a head stock 1 which is fixedly arranged on the machine bed 17and has a grinding spindle 2 inserted therein. Spindle 2 is coupled to adriving unit 3 and carries a grinding disc 4. The grinding disc 4 isarranged within a protective hood 8 which by means of supporting flanges5 and 6 is connected to the machine bedl7. Those parts of the protectivehood 8 which are connected to the two supporting flanges 5 and 6 areadapted in the axial direction of the grinding spindle to be separatedfrom each other so that the supporting flange 6 after having beendisconnected from the machine can be displaced in the right-handdirectionwith regard to FIG. 2 for purposes of exchanging the grindingdisc. The outer machine cover 7 is at the right-hand operating side(with regard to FIG. 1) provided with an outer hood 14 which is adaptedto be moved in upward direction to the position indicated by dot-dashlines. For purposes of opening and closing the hood 8, there is withinthe machine cover provided a transmission 15 with gear rack 15a and witha gear 15b which is stationarily joumalled with regard to the frame, andwith a pivotal arm 15c pivotally connected to outer hood 1'4 and with adriving cylinder 15d. As support for the work piece, according to thespecific embodiment illustrated, there is provided a carriage 16 with awork piece support 160. The carriage 16 is arranged below the stationarygrinding wheel head 1 and is displaceable in a direction trans verse tothe grinding spindle axis.

As will be seen from FIGS. 1 and 2, a cap 9 is arranged on theprotective hood 8 and has its lateral parts 10 and extend around theupper and front section of the protective hood 8. Cap 9 is adapted to bedisplaced in the direction transverse to the grinding spindle axis asindicated by the arrow A in FIG. 1. The lower front edge 9a of cap 9which is arranged within the region of the working opening of hood 8 onthe work piece side should be kept at a predetermined slight distancefrom the circumference of the grinding disc 4 and, more specifically, inconformity with the decreasing grinding diameter in the direction of thearrow A. When inserting a new or larger grinding disc, cap 9 is returnedto its corresponding starting position. On the front side of cap 9 thereis within the region of the edge provided a feeding device 9b for acoolant, the mouth of the cooling device which points downwardly shouldlikewise be kept at a predetermined distance from the circumference ofthe grinding disc. The feed ing device for the coolant will to this endtake part in the adjusting movement of cap 9.

A separate adjusting device 12 with a threaded drive in the form of athreaded spindle l3 and a nut 13a connected to the cap 9 is provided forthe latter. This adjusting device is, in a manner to be describedfurther below, connected to the feeding device 20 of a dressingapparatus 18 which is arranged behind the grinding disc. The dressingtool 19 of the device 18 extends through a cutout in the rear wall ofthe protective hood 8 and is adapted to be displaced in the direction ofthe arrow B (FIG. 1) for engagement with the circumference of thegrinding disc.

As diagrammatically illustrated in FIG. 3, the feeding device of thedressing apparatus 18 comprises a fast traverse feeding device 21 in theform of a fluidoperable cylinder piston system, and also comprises afine adjusting device 22 in the form of a screw drive with threadedspindle 22a and nut 22b which is connected to the dressing tool carrier19a and is connected to the piston rod of the fluid-operable cylinderpiston system 21. By means of the fast traverse feeding device, the toolcarrier 19a is, in conformity with arrow B, advanced to a startingposition for a dressing operation. This starting position is determinedby a non-variable abutment position of the piston in the cylinder pistonsystem 21 and by the respective relative position between spindle 22aand nut 22b. Inasmuch as the starting position for each dressingoperation simultaneously represents the end position of the precedingdressing operation, which end position was reached by a correspondingrotation of the spindle, the fine feeding of the tool carriage 19a iseffected during the dressing operations following each other always onlyin the direction of the arrow B and, more specifically, independently ofthe advance and return strokes of the fast traverse feeding devicecarried out between the individual dressing operations. For this reason,the fine feeding device also is suited as position indicator for asuccessive postguiding of cap 9 in conformity with the decreasingdiameter of the grinding disc.

As drive for the fine feeding device, according to the specific showingin the drawings, a pawl ratchet mechanism 3 with ratchet wheel 23a andpawl 23b as well as with a lifting element in the form of afluid-operable cylinder piston system 230 is provided. The ratchet wheel23a is through the intervention of a diagrammatically indicated driveconnection 24 connected to a stepdown transmission 25 which lattercomprises a drive wheel 25a for the spindle 22a of the fine feedingdevice.

For purposes of limiting the stroke of the pawl 23b in conformity withdifferent feeding end positions of the dressing tool 19, there isprovided an adjustable abutment device 26 with two abutments 26a, 26brespectively adjustable by two fluid-operable cylinders between twopositions. By means of these two abutments, it is possible to adjust atotal of three different feeding end positions I, II and III of the pawl13b.

The adjusting device 12 of cap 9 is as to its drive synchronous with thefine feeding device of the dressing apparatus. This may be realized,according to the specific showing in FIG. 3, by a direct connection ofthe spindle 13 through the intervention of a stepdown transmission 12and a coupling 12b with the transmission connection 24 of the finefeeding device 22. Inversely, as likewise indicated in FIG. 3, for theadjusting device 12 of cap 9 there may be provided a pawl ratchetmechanism 27 which, as assumed in the specific embodiment, may as to alldetails correspond to the ratchet mechanism 23 of the fine feedingdevice of the dressing tool so that a further description of the ratchetmechanism 27 does not appear to be necessary.

The synchronization between adjusting device 12 and fine feeding device22 is in the last mentioned instance effected by a common feedingcontrol device 28 of thefluid-operable cylinder piston systemspertaining to the two ratchet mechanisms 23 and 27. A correspondingcommon control circuit 29 is provided for the equal stroke limitation ofthe pawls.

If the adjusting device 12 has a drive of its own, for instance in theform of a pawl ratchet mechanism 27, the pawl ratchet mechanism or acorresponding different drive for the fine feeding device may beomitted. In such an instance the coupling 12b will take over thesynchronization and will also simultaneously effect the drive of thefine feeding device. Such a design has the advantage that only onesingle driving device for the fine feeding device and for the adjustingdevice will be necessary and this holds true also for a plurality ofexchangeable dressing devices. These dressing devices will in such aninstance require primarily only the screw drive of the fine feedingdevice. The coupling 12b is for such exchange of the dressing deviceexpediently designed as plug coupling or another easily detachabledesign. In certain circumstances, however, it may be necessary andexpedient to provide the dressing device with fast traverse and finefeeding means including a pawl ratchet mechanism or the like in the formof exchangeable structural units as has been indicated in FIG. 3 by thedot-dash line 30. For purposes of exchanging the grinding disc, it ismerely necessary to open up the feeding and control connections of thepawl ratchet mechanisms.

In connection with the present invention, particular importance isattached to a safe mounting and guiding of the adjustable cap 9 in casethe grinding disc should break. Inasmuch as it is practically impossibleto provide such a rigid design of the anchoring of the cap 9 that itwill be able towithstand or absorb such high load, an energy consuminganchoring or connection is to be preferred which in case of a break ofspindle 13 or of another driving element of the cap 9 will convert intoa deforming work the energy of movement of the cap which is thrownforwardly by pieces of the broken grinding disc. To this end, as shownin FIG. 1, the lateral part of cap 9 is provided with a guidingconnection having a slot 31 and pin 32. The pin 32 is connected to thelateral wall of hood 8 which wall is located below pin 32. Pin 32supports cap 9 in vertical direction. Within the region of the rear pinposition within the slot, which position corresponds to the cap positionfarthest away from the grinding disc, there is provided a slot support33 which tapers in a wedge-like manner to less than the diameter of thepin. It is into this slot section 33 that the pin will be pressedsuccessively when cap 9 which is torn loose is thrown toward the front.In this connection a considerable amount of kinetic energy is convertedinto deforming work and is thus made harmless with regard to possiblefurther damage to the machine.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular showing in the drawings but alsocomprises any modifications within the scope of the appended claims.What is I claimed is:

1. In a grinding machine having a grinding disc, a

means connected to said dressing device for adjustment thereof, secondmeans connected to said element for adjustment thereof, and third meansoperatively interconnecting said first and second means for correlatingthe adjustments of said dressing device and said element, a hood for thegrinding disc respectively a coolant supply nozzle mounted to directcoolant to the working region of the grinding disc, said hoodrespectively said nozzle comprising said element.

2. In a grinding machine having a disc, a dressing device for thegrinding disc and an element separate from said dressing device andadjustable in conformity with the diameter of the grinding disc, saidelement comprising a hood for the grinding disc and a coolant supplynozzle mounted to direct coolant to a working region of the grindingdisc, first means connected to said dressing device for adjustmentthereof, second means connected to said element for adjustment thereof,and third means operatively interconnecting said first and second meansfor correlating the adjustments of said dressing device and saidelement, said first means comprising a fast traverse feed means and afine feed means operable sequentially, said third means operatively onlyconnecting said second means to said fine feed means.

3. A grinding machine according to claim 2 in which said fast traversefeed means is in the form of a cylinder-piston system and said fine feedmeansis in the form of a screw drive system coupled thereto, saidcylinder-piston system having fixed end positions, said third meansoperatively connecting said screw drive system to said second means.

4. In a grinding machine having a grinding disc, a dressing device forthe disc and an element separate from said dressing device andadjustable in conformity with the diameter of the disc; first meansconnected to said dressing device for adjustment thereof, second meansconnected to said element for adjustment thereof, and third meansoperatively interconnecting said first and second means for correlatingthe adjustments of said dressing device and said element, a hood forsaid disc, said hood having a movable part and a coolant supply nozzlemounted thereon to direct coolant to the working region of the disc,said part and nozzle comprising said element, said second meanscomprising an adjusting screw threadedly engaging said element, saidfirst means comprising a fast traverse feed means and a fine feed means,and said third means connecting said adjusting screw to said fine feedmeans.

5. A grinding machine according to claim 4 in which said fast traversefeed means comprises a cylinder and a piston reciprocable therein, afeed screw connected to the piston and a nut on the feed screw connectedto the dressing device, said third means operatively interconnectingsaid feed screw and said adjusting screw.

6. A grinding machine according to claim 5 in which said third meanscomprises a geared transmission.

7. A grinding machine according to claim 5 which includes a ratchetwheel, a geared transmission connecting said ratchet wheel to said feedscrew, a drive pawl for the ratchet wheel, and stroke drive meansconnected to said pawl for the actuation thereof.

8. A grinding machine according to claim 7 which includes adjustableabutment means operatively associated with said stroke drive means forcontrolling the stroke thereof thereby to control the fine feeding ofsaid dressing device.

9. A grinding machine according to claim 8 in which said abutment meansincludes a plurality of abutments at least one of which is selectivelymoveable between effective and ineffective positions.

10. A grinding machine according to claim 5 which includes a ratchetdisc connected to said adjusting screw, drive pawl means for saidratchet wheel, and stroke drive mechanism connected to said pawl meansfor the actuation thereof.

11. A grinding machine according to claim 10 which an adjustableabutment device operatively associated with said stroke drive mechanismto control the adjustment of said element.

12. A grinding machine according to claim 11 in which said-abutmentdevice comprises a plurality of abutment elements at least one of whichis selectively moveable between effective and inefiective positions.

13. A grinding machine according to claim 5 which includes a ratchetwheel connected to each of said adjusting screw and feed screw, a drivepawl for each ratchet wheel, a stroke drive means connected to each pawlfor the actuation thereof, and means for simultaneously controlling bothof said stroke drive means.

14. A grinding machine according to claim 4 in which said dressingdevice and said fine feed means form a single exchangeable structuralunit.

15. In a grinding machine having a grinding disc, a dressing device forthe disc and an element separate from said dressing device andadjustable in conformity with the diameter of the disc; first meansconnected to said dressing device for adjustment thereof, second meansconnected to said element for adjustment thereof,.and third meansoperatively interconnecting said first and second means for correlatingthe adjustments of said dressing device and said element, a hoodenclosing at least a portion of said disc, said hood hav-- ing a movablepart and a coolant supply nozzle on said part, said movable part andnozzle comprising said element, pin and slot means guidingly connectingsaid hood and said part thereof, said slot extending in the direction ofadjustment of said part and tapering inwardly in the direction in whichthe pin moves therein as said part moves away from saiddisc, said slottapering inwardly to a dimension smaller than the diameter of said pin.

. i i l

1. In a grinding machine having a grinding disc, a dressing device forthe grinding disc and an element separate from said dressing device andadjustable in conformity with the diameter of the grinding disc; firstmeans connected to said dressing device for adjustment thereof, secondmeans connected to said element for adjustment thereof, and third meansoperatively interconnecting said first and second means for correlatingthe adjustments of said dressing device and said element, a hood for thegrinding disc respectively a coolant supply nozzle mounted to directcoolant to the working region of the grinding disc, said hoodrespectively said nozzle comprising said element.
 2. In a grindingmachine having a disc, a dressing device for the grinding disc and anelement separate from said dressing device and adjustable in conformitywith the diameter of the grinding disc, said element comprising a hoodfor the grinding disc and a coolant supply nozzle mounted to directcoolant to a working region of the grinding disc, first means connectedto said dressing device for adjustment thereof, second means connectedto said element for adjustment thereof, and third means operativElyinterconnecting said first and second means for correlating theadjustments of said dressing device and said element, said first meanscomprising a fast traverse feed means and a fine feed means operablesequentially, said third means operatively only connecting said secondmeans to said fine feed means.
 3. A grinding machine according to claim2 in which said fast traverse feed means is in the form of acylinder-piston system and said fine feed means is in the form of ascrew drive system coupled thereto, said cylinder-piston system havingfixed end positions, said third means operatively connecting said screwdrive system to said second means.
 4. In a grinding machine having agrinding disc, a dressing device for the disc and an element separatefrom said dressing device and adjustable in conformity with the diameterof the disc; first means connected to said dressing device foradjustment thereof, second means connected to said element foradjustment thereof, and third means operatively interconnecting saidfirst and second means for correlating the adjustments of said dressingdevice and said element, a hood for said disc, said hood having amovable part and a coolant supply nozzle mounted thereon to directcoolant to the working region of the disc, said part and nozzlecomprising said element, said second means comprising an adjusting screwthreadedly engaging said element, said first means comprising a fasttraverse feed means and a fine feed means, and said third meansconnecting said adjusting screw to said fine feed means.
 5. A grindingmachine according to claim 4 in which said fast traverse feed meanscomprises a cylinder and a piston reciprocable therein, a feed screwconnected to the piston and a nut on the feed screw connected to thedressing device, said third means operatively interconnecting said feedscrew and said adjusting screw.
 6. A grinding machine according to claim5 in which said third means comprises a geared transmission.
 7. Agrinding machine according to claim 5 which includes a ratchet wheel, ageared transmission connecting said ratchet wheel to said feed screw, adrive pawl for the ratchet wheel, and stroke drive means connected tosaid pawl for the actuation thereof.
 8. A grinding machine according toclaim 7 which includes adjustable abutment means operatively associatedwith said stroke drive means for controlling the stroke thereof therebyto control the fine feeding of said dressing device.
 9. A grindingmachine according to claim 8 in which said abutment means includes aplurality of abutments at least one of which is selectively moveablebetween effective and ineffective positions.
 10. A grinding machineaccording to claim 5 which includes a ratchet disc connected to saidadjusting screw, drive pawl means for said ratchet wheel, and strokedrive mechanism connected to said pawl means for the actuation thereof.11. A grinding machine according to claim 10 which an adjustableabutment device operatively associated with said stroke drive mechanismto control the adjustment of said element.
 12. A grinding machineaccording to claim 11 in which said abutment device comprises aplurality of abutment elements at least one of which is selectivelymoveable between effective and ineffective positions.
 13. A grindingmachine according to claim 5 which includes a ratchet wheel connected toeach of said adjusting screw and feed screw, a drive pawl for eachratchet wheel, a stroke drive means connected to each pawl for theactuation thereof, and means for simultaneously controlling both of saidstroke drive means.
 14. A grinding machine according to claim 4 in whichsaid dressing device and said fine feed means form a single exchangeablestructural unit.
 15. In a grinding machine having a grinding disc, adressing device for the disc and an element separate from said dressingdevice and adjustable in conformity with the diameter of the disc; firstmeans connected to said dressing device for adJustment thereof, secondmeans connected to said element for adjustment thereof, and third meansoperatively interconnecting said first and second means for correlatingthe adjustments of said dressing device and said element, a hoodenclosing at least a portion of said disc, said hood having a movablepart and a coolant supply nozzle on said part, said movable part andnozzle comprising said element, pin and slot means guidingly connectingsaid hood and said part thereof, said slot extending in the direction ofadjustment of said part and tapering inwardly in the direction in whichthe pin moves therein as said part moves away from said disc, said slottapering inwardly to a dimension smaller than the diameter of said pin.